I am using spark 1.5. I want to create a data frame from a file in HDFS. The HDFS file contains json data with a large number of fields in a sequence input file format.
Is there a way to do t
Tag: Hadoop
Hadoop cluster time synchronization
1. Cluster time synchronization
Find a machine, as a practical server, all machines will synchronize with the cluster time regularly, for example, synchronize the time every ten minutes.
1.1 Steps
The difference between Hadoop – Reduce Task and Reducer
“The reducer is different from the reduction task. The reducer can run multiple reduction tasks”. Can someone explain this with the following example?
foo.txt: Very good, this is the foo file
Hadoop – Search Specific Text in String – Hive
/google/gmail/inbox
/google/drive/map
/google/apps
/yahoo/news/cricket
/yahoo/mail/
/yahoo/sports
/wiki/ind/jack
/wiki/us/jil I need to get the required page group .If I use hive query to se
Hadoop – write Spark data frame as inlaid to S3 instead of creating _temporary folder
Using pyspark I am reading a data frame from a parquet file on Amazon S3
dataS3 = sql. read.parquet(“s3a://” + s3_bucket_in) This is no problem. But then I try to write data
dataS3.writ
Hadoop – HBase Oldwals: What is it, how can I clean it?
There is not enough space in our small hadoop cluster, so I am checking the disk usage on HDFS and I found that most of the space is occupied by the /hbase/oldWALs folder.
I have checked the
Hadoop – Apache Spark runs Spark-shell on Yarn error
I downloaded spark-2.1.0-bin-hadoop2.7.tgz from http://spark.apache.org/downloads.html. I have Hadoop HDFS and YARN with $ start-dfs.sh and $start-yarn.sh start. But running $spark-shell –master ya
Hadoop gen1 vs Hadoop gen2
I am a bit confused about the location of tasktracker in Hadoop-2.x.
The daemons in Hadoop-1.x are namenode, datanode, jobtracker, taskracker and secondarynamenode
The daemons in Hadoop
Hadoop – How do I check if HDFS is running?
I want to see if Hadoop’s hdfs file system is working properly. I know that jps lists the running daemons, but I don’t actually know which daemons to look for. < p>
I ran the following comman
The second bomb of those pits of Hadoop CDH
Fuck. . . . Can’t connect to the datanode. I don’t know why the datanode can’t be connected. .
2019-07-19 16:10:00,156 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: hadoop102